Tree Growth
Shade Loss
Trim ROI
25‑Yr Impact
DSIRE Adj.
Determines annual sun hours and DSIRE incentive value per kWh.
Obstruction Details (Tree or Structure)
Trimming Options
25‑Year Net Impact of Shade Management
$0
Unmatched Shade Modeling Precision
Generic solar calculators ignore tree growth — we simulate it dynamically. Our tool layers three exclusive datasets:
- USFS Tree Growth Curves: Species‑specific height and crown spread projections over 25 years.
- Solar Position Algorithm (NREL): Hourly sun angles for your latitude to compute shadow length.
- DSIRE Incentive Decay: Adjusts lost production value by state SREC and rebate structures.
How Shade Loss & Trim ROI Are Calculated
- Shadow Length: Tree Height × cot(Solar Elevation Angle) based on latitude and azimuth.
- Shade Fraction: Overlap between shadow footprint and panel area (simplified trigonometric model).
- Annual Energy Loss: Unshaded Production × Shade Fraction × Seasonality Factor.
- Tree Growth: Height(t) = Current Height + Species Growth Rate × Years.
- Trim Payback: (Avoided Energy Loss Value × Years) / Cumulative Trimming Cost.
Shade & Tree Growth FAQ
How fast will my tree grow and impact solar?
Fast‑growing species (maple, poplar) add 1.5‑2 ft/year, reducing solar output by an additional 1‑2% annually. Our tool uses USFS growth data for accuracy.
Is trimming worth the cost?
In high DSIRE incentive states (CA, MA, NJ), trimming can yield a 200‑400% ROI over 10 years. Our premium report pinpoints the exact trim year for maximum net benefit.
Does shade affect state incentives?
Yes — SREC and performance‑based incentives pay per kWh generated. Shade directly reduces incentive revenue. We adjust DSIRE values accordingly.
What if the tree is on a neighbor's property?
Our tool still quantifies the loss. Some states (CA, MA) have solar shade laws; premium users get a summary to discuss with neighbors or legal counsel.